U.S. patent application number 11/137459 was filed with the patent office on 2006-11-30 for hydration monitoring circuitry for ph sensors.
Invention is credited to Charles S. Bankert, Leo R. Roucher, Jeffery D. Schipper, Ross Tsukashima, Thomas Germain Wallner, Erich H. Wolf.
Application Number | 20060270936 11/137459 |
Document ID | / |
Family ID | 37464384 |
Filed Date | 2006-11-30 |
United States Patent
Application |
20060270936 |
Kind Code |
A1 |
Tsukashima; Ross ; et
al. |
November 30, 2006 |
Hydration monitoring circuitry for pH sensors
Abstract
The present invention pertains to an apparatus for evaluating
the signal strength from the pH sensor to determine whether the
sensor is hydrated sufficiently to accurately measure pH. This is
accomplished by utilizing circuitry that periodically sends a low
voltage signal to a suitable pH sensor and then receiving the
resulting waveforms which are analyzed by a processing receiver.
The electrical connection between a suitable pH sensor and
hydration monitoring circuitry is generally hard wired. In one
embodiment, a processing receiver is coupled with the hydration
monitoring circuitry as a single apparatus. In a second embodiment,
the processing receiver can be independent and located remote from
the hydration monitoring circuitry. In this embodiment, the
hydration monitoring circuitry and the processing receiver are
electrically connected using either hard wired techniques or
wireless technology. In addition, the processing receiver can
include data recording capability.
Inventors: |
Tsukashima; Ross; (San
Diego, CA) ; Wolf; Erich H.; (Vista, CA) ;
Schipper; Jeffery D.; (Ramona, CA) ; Bankert; Charles
S.; (Oceanside, CA) ; Roucher; Leo R.; (Rancho
Santa Fe, CA) ; Wallner; Thomas Germain; (San Marcos,
CA) |
Correspondence
Address: |
MICHAEL E. KLICPERA
PO BOX 573
LA JOLLA
CA
92038-0573
US
|
Family ID: |
37464384 |
Appl. No.: |
11/137459 |
Filed: |
May 25, 2005 |
Current U.S.
Class: |
600/481 |
Current CPC
Class: |
A61B 5/1495 20130101;
A61B 5/145 20130101; A61B 5/1473 20130101; A61B 5/14542 20130101;
A61B 2560/0276 20130101; A61B 2562/02 20130101; A61B 5/14539
20130101 |
Class at
Publication: |
600/481 |
International
Class: |
A61B 5/02 20060101
A61B005/02 |
Claims
1. An apparatus for monitoring the hydration level of a pH sensor,
said apparatus comprising: a hydration monitoring circuit; a pH
sensor; an electrically communication means between said hydration
monitoring circuitry and said pH sensor; and a processing receiver,
said processing receiver in communication with said hydration
monitoring circuitry.
2. The apparatus for monitoring the hydration level as recited in
claim 1, further comprising that said processing receiver includes
a data recorder.
3. The apparatus for monitoring the hydration level as recited in
claim 1, wherein said hydration monitoring circuitry and said
processing receiver is incorporated in a single apparatus.
4. The apparatus for monitoring the hydration level as recited in
claim 1, wherein said hydration monitoring circuitry monitors said
hydration level on a specified periodic frequency.
5. The apparatus for monitoring the hydration level as recited in
claim 1, wherein said processing receiver is in real time
communication with said hydration monitoring circuitry.
6. The apparatus for monitoring the hydration level as recited in
claim 1, wherein said processing receiver is in wireless
communication with said hydration monitoring circuitry.
7. The apparatus for monitoring the hydration level as recited in
claim 6, wherein said wireless communication is conducted in
real-time.
8. The apparatus for monitoring the hydration level as recited in
claim 1, wherein said processing receiver has the capability to
analyze the hydration level of said self-condensing sensor.
9. The apparatus for monitoring the hydration level as recited in
claim 2, further comprising a removable data storage medium, said
removable data storage designed to communicate with said processing
receiver with data recorder, said removable data storage medium
further designed to store recorded pH measurements monitored by
said self-condensing pH sensor over a period of time.
10. The apparatus for monitoring of pH as recited in claim 1,
wherein said processing receiver includes a visual or audible
alarming means that is generated if the sensor is not sufficiently
hydrated to provide reliable pH measurements.
11. The apparatus for monitoring of pH as recited in claim 1,
wherein said processing receiver includes a visual or audible
alarming means that is generated if upon the occurrence of a
specific waveform.
12. The apparatus for monitoring of pH as recited in claim 1,
wherein said processing receiver includes a means to terminate the
recording of pH data obtained from the pH sensor if said pH sensor
is not sufficiently hydrated to provide reliable pH
measurements.
13. An apparatus for monitoring the hydration level and determining
the reliability of a pH sensor, said apparatus comprising: a
hydration monitoring circuit; a pH sensor; an electrical
communication means between said hydration monitoring circuitry and
said pH sensor; and a processing receiver, said processing receiver
in communication with said hydration monitoring circuitry; and an
algorithm or other means to determine if the sensor is sufficiently
hydrated to provide reliable pH measurements.
Description
FIELD OF THE INVENTION
[0001] The field of art to which this invention relates is in the
monitoring of pH using a sensor in corporeal and industrial
applications. More specifically, the present invention monitors and
detects the hydration level of pH sensors for determining the
accuracy and strength of data generated from the sensor.
BACKGROUND OF THE INVENTION
[0002] Certain clinical methods and apparatus are known in the
prior art for 24 hour monitoring of intra and supra esophageal pH
in patients with suspected reflux disease or laryngopharyngeal
disorders.
[0003] An example of a system for ambulatory 24 hour recording of
gastroesophageal reflux is the Digitrapper.TM. System (manufactured
by Synectics Medical AB, in Stockholm, Sweden) used with glass or
Monocrystant.TM. pH catheters (as described in U.S. Pat. No.
4,119,498) and with the analysis software EsopHogram.TM. (by
Gastrosoft, Inc. in Dallas, Tex.). These prior art systems
typically measure pH in the esophageal tract with an
intra-esophageal catheter and generate reports regarding esophageal
exposure of gastric fluid. Systems such as these are primarily
designed to measure reflux moving past the Lower Esophageal
Spincter (LES) into the esophagus.
[0004] Sensors that measure and detect reflux above the Upper
Esophagel Spincter (UES) have been less successful due to problems
with traditional pH sensors malfunctioning when direct fluid
contact is lost. Problems such as drift and artifacts (sometimes
referred to as pseudoreflux events) are common complaints when
attempting to measuring pH above the UES.
[0005] Currently there are no pH monitoring devices that teach how
or have the capability to simultaneously measure pH data, monitor a
pH sensors level of hydration and determine the reliability of the
measurement
[0006] Because all pH sensors require moisture to function, one way
to determine if the sensor is functioning properly would be to
detect the presence of a liquid through the use of electrical
impedance. One such system as described by Anders Essen-Moller,
(U.S. Pat. No. 5,479,935) detects the presence or absence of liquid
reflux through the use of separate electrical electrodes
incorporated into a catheter that is inserted into the esophagus.
These catheters require dedicated electrodes and additional
circuitry to function properly which increases cost and complexity.
Additionally, because it is not directly connected to the pH
sensor, it can only infer that the pH sensor is working reliably
and the data is accurate if adequate levels of hydration are
detected.
SUMMARY OF THE INVENTION
[0007] The present invention pertains to an apparatus for
evaluating the signal strength from a suitable pH sensor to
determine whether the sensor is hydrated sufficiently to accurately
measure pH. This is accomplished by utilizing a novel circuitry
that periodically sends a low voltage signal to a suitable pH
sensor and then receiving the resulting waveforms which are
analyzed by a processing receiver. The electrical connection
between a suitable pH sensor and hydration monitoring circuitry is
generally hard wired. In one embodiment, a processing receiver is
coupled with the hydration monitoring circuitry as a single
apparatus. In a second embodiment, the processing receiver can be
independent and located remote from the hydration monitoring
circuitry. In this embodiment, the hydration monitoring circuitry
and the processing receiver are electrically connected using either
hard wired techniques or wireless technology. In all embodiments of
the present invention, the monitoring and monitoring of the
hydration level is conducted in real-time. In addition, the
processing receiver can include data recording capability.
[0008] It is the object with the present invention to provide a
means of which a specialized circuitry, when used in combination
with a suitable pH sensor, can be used to determine adequate signal
strength for reliable pH measurement.
[0009] These and other features, aspects and advantages of the
present invention will become better understood with reference to
the following descriptions and claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] FIG. 1 is a schematic representation of the electrical
circuit used in the transmitting device for monitoring the
hydration level of a suitable pH sensor.
[0011] FIG. 2 is a perspective representation of a processing
receiver with optional data recording capability.
[0012] FIG. 3 is a graphic representation of the hydration
monitoring waveform demonstrating the expected wave format for a
non-hydrated, partially hydrated and fully hydrated suitable pH
sensor.
[0013] FIG. 4 is one example of a pH sensor that is suitable for
monitoring of hydration and signal strength using the hydration
monitoring circuitry and the processing receiver.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0014] FIG. 1 demonstrates a schematic representation of a
hydration monitoring circuit 10 used for monitoring and detecting
the hydration level of a suitable pH sensor 20. The hydration
monitoring circuit 10 periodically (or on a specified periodic
frequency) sends a small electrical waveform (approximately 0.5V
Peak to Peak waveform) through input circuitry 12 and electronic
communication means 16, 18 to a suitable pH sensor 20. After the
low voltage signal is sent to the suitable pH sensor 20, output
circuitry 14 analyzes the resulting wave forms detecting fully
hydrated, partially hydrated and non-hydrated conditions. If the
analysis of the data shows a relatively stable reading from peak to
peak, the pH data is accepted can be recorded. If the data shows a
relatively high peak to peak reading the recording of pH data can
be terminated and the apparatus can signal visually or audibly that
the data may be unreliable.
[0015] FIG. 2 is a perspective representation of a processing
receiver 30 with optional data recording capability 32. The
processing receiver 30 is typically designed as the operator
interface between both the clinician and patient, and can include a
means for recording pH data and user events during an ambulatory
study. The processing receiver 30 is usually battery powered, and
includes a clock to keep and display time, memory to store patient
data, buttons for recording patient events, and an electronic
connection to a hydration monitoring circuitry 10. This electronic
connection can be wired or wireless. Additionally, the recorder
typically provides a way to upload the data to a PC for storage and
analysis.
[0016] The processing receiver 30 includes one or more
microprocessors that are typically low power devices such as
Microchip model 16F and 18F series controllers, and the ATMEL 8051
family of devices. Timekeeping can be accomplished by the
microprocessor, or accomplished by a dedicated time chip such as
the Dallas DS1338 real time clock. To keep power consumption to a
minimum, LCD displays such as the Optrex DMC-16204 can be utilized.
Wireless communication can be accomplished in a variety of means,
from frequency shift keying techniques to advanced spread spectrum
designs.
[0017] The processing receiver 30 includes software that is
specifically designed to analyze waveforms generated by the
waveform input 12 of the hydration monitoring circuitry 10. The
software is programmed to initiate a visual or audible alarm and/or
stop recording pH data upon the occurrence of unreliable waveforms.
Furthermore, the processing receiver 30 can have the capability to
monitor and record pH data, in real-time, generated by the pH
sensor. Both the hydration monitoring data and the pH data obtained
from the sensor can be further downloaded onto the recording
capability 32. Recording capability 32 can one of the typical
marketed non-volatile memory devices such as the Secure Digital.TM.
(SD), Multimedia Card.TM. (MMC), Compact Flash.TM., mart Media.TM.,
or can be a proprietary developed data card. Other types of
non-voltatile media that can be used as recording capability 32 are
CD-ROMs, DVDs, and hard disks.
[0018] FIG. 3 is a graphic representation of the hydration
monitoring results demonstrating the expected wave format for a
non-hydrated 40, partially hydrated 42 and fully hydrated 46 states
of the pH sensor. On the left side of the graph, the waveform 40
demonstrates that the suitable pH Sensor is not hydrated. In the
middle of the graph, the waveform 42 demonstrates that the suitable
pH Sensor is partially hydrated. On the right side, the waveform 46
demonstrates that the suitable pH Sensor is fully hydrated. If the
suitable pH sensor loses hydration or malfunctions, data generated
may be unreliable. The hydration monitor circuit 10 periodically
sends a low voltage signal through input circuitry 17 and
electronic communication means 16, 18 to the pH sensor 20. After
the low voltage signal is sent to the pH sensor 20, output
circuitry 19 sends the composite signal to the processing receiver
30 for analysis the resulting waveforms.
[0019] FIG. 4 is just one example of a pH sensor that is suitable
for hydration monitoring. This pH sensor is being provided only for
the purpose of an example as the Applicants assert that other pH
sensor designs can utilize and benefit from the present invention.
For this purpose, the example pH sensor is a self-condensing design
with an outer tubular member 21 and an inner tubular member 22.
Both are usually fabricated by an extrusion or dip coating process
using a variety of polymeric materials. Located within the inner
tubular member 22 is an antimony element 23. The antimony element
23 is engaged at its proximal end to an electronic communication
means 24. A reference wick 25 is located between the inside surface
of the outer tubular member 21 of the example pH sensor 20 and the
outer surface of the inner tubular member 22. The reference wick 28
is impregnated with an ion conduction fluid 28. Typical conduction
fluids include those that contain sodium chloride or potassium
chloride and water. Located proximally, from the proximal end of
the antimony element 23 is a reference element 26. Said reference
element 26 is primarily composed of a silver core surrounded with a
coating of silver chloride. The reference element 26 is engaged to
an electrical communication means 27, e.g. typical wire that
extends to the proximal end of the outer tubular member and
terminates in a typical electrical connector.
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